A new report from Policy Exchange claims that the judiciary are effectively paralysing our armed forces. It goes as far as to imagine a potential enemy following a strategy of "legal attacks" in order to weaken Britain on the battlefield. Ironically, as the government is currently selling London as a centre for international litigation, this might mean that a good war is just what we need to boost the economy.

Except none of this will actually happen. The report vastly misinterprets the effects of judgments and generally misconstrues International Public Law, International Customary Law and English common law. More importantly, the report's authors, Thomas Tugenhadt and Laura Croft, fail to appreciate the constitutional implications of their subject. What they call "legal creep" would be more accurately described as "making government accountable to the law".

The report makes two headline assertions: (1) The common law concept of negligence has been extended to the military and (2) both the military and third parties have become subject to the European Convention on Human Rights (ECHR). Both of these are true. But that doesn't mean that effective defence of the realm is a thing of the past.

The central case cited in respect of both claims is Smith v Ministry of Defence. Smith concerns (amongst several different issues) a group of British soldiers suing the MoD after the tank they were operating was hit by a shell from another British tank. The Supreme Court held that (a) the MoD had a duty of care towards the soldiers and (b) that the claim should not be struck out based on combat immunity. Tugenhadt and Croft argue that to apply the civilian concept of negligence to the MoD would reduce the military's operational capability.

But that's not actually what the court decided. It was held that a duty of care existed, not that the MoD were necessarily guilty of negligence. To say that this will constrain operational efficiency is to misunderstand English tort law. First, it's not soldiers in the field who are being held liable, it's the MoD itself. Second, despite the existence of a duty, Smith's suit can't succeed unless that duty has been breached. This will depend on whether the court believes a reasonable person (or organisation), with the same level of expertise as the MoD, would have failed to equip the tanks with the technology necessary to stop them accidentally shooting each other. This doesn't place an excessive burden on the MoD. It holds it accountable for gross errors which lead to people getting hurt. To my mind, equipping Challenger tanks with combat recognition equipment inferior to that used in Age of Empires II is a fairly stratospheric act of negligence, but that's a matter for another court.

It's also wrong to say, as Tugenhadt and Croft do, that this judgement weakens the principle of combat immunity. If anything, from a legal point of view, the principle is strengthened through the court's clarification. The principle was endorsed by the court but construed narrowly, so it only applies to soldiers in the field, rather than bureaucrats making procurement decisions thousands of miles behind the front line.

The extension of the ECHR raises a different issue. It probably does, theoretically, place an extra legal burden on the MoD. It means that the MoD must respect the human rights of both British soldiers and foreign nationals. This doesn't mean that soldiers won't be able to kill hostile combatants. But it does mean that the MoD is financially liable if British soldiers commit war crimes. But this doesn't actually change what soldiers can and can't do in the field. Basic human rights are already protected by the Law of Armed Combat. Soldiers haven't suddenly been prevented from killing civilians or torturing prisoners - they couldn't do that anyway. What is different now is that, as well as the individual soldiers being liable for prosecution, the MoD will have to pay damages to the victims. Accountability is extended from the individual to the institution, which either condoned his actions or failed to ensure adequate oversight.

Tugenhadt and Croft's proposed solution, that the UK derogate from the ECHR in deployed situations, would be both ineffective and damaging. The obligations, from which Tugenhadt and Croft would derogate, would still bind Britain as a result of the UN Charter, the International Covenant on Civil and Political Rights, International Customary Law and our own common law.

But the purely legal implications are less important than the wider constitutional issues. The Supreme Court's judgement in Smith is not about limiting individual soldiers' and field commanders' operational discretion. It is about holding the government accountable for it's actions in war, as we do in peace.

This is important. If we are to have accountable government, then all parts of government must be accountable. The HRA established that the ECHR is not merely a new rule but an adamant thread; the life blood in the corpus of English law. It made explicit that which had been implicit, but nonetheless vital: Respect for human dignity and individual rights is the bedrock of our society.

To exempt the military is to suggest that the Second Estate somehow has a special status. This was the case in the past, when rulers could declare a state of war to enforce repressive policies. But society has advanced. When it comes to the rule of law, no one is special. Our fundamental law needs to be flexible and dexterous but it also needs to apply equally to all. Even lawmakers themselves.